Finally, Roland released an update to the SCC-1. The board itself is labeled the SCC-1A. It has the extra sounds of the JV-30 Keyboard but does not support capital tone fallback. This was a feature patented by Yamaha apparently.

Can that be true?Yamaha patented the Peanut-butter Jelly sandwich so no one can use that...

I can't comment on the tech mumbo-jumbo (lacking in both knowledge and interest in these features ) but in games I always prefer how the mk1 sc-55 sounds unless the game needs the mk2 higher polyphony. I almost never power my mk2 tbh (and as a sidenote I also removed the MU-80 from my gaming midi tower, powering it was more scarce than the mk2 unit...)

James-F wrote:Can that be true?Yamaha patented the Peanut-butter Jelly sandwich so no one can use that...

Unfortunately, yes. It's referenced in one or two old USENET posts, as well as in Stanley Jungleib's, "General MIDI" book.

keropi wrote:lacking...interest in these features )

Boooo! These are the types of detailed discussions that made the QuestStudios forum so great.

...but in games I always prefer how the mk1 sc-55 sounds...

Interesting. I actually prefer the additional clarity of the SC-55mkII, and find its soundstage to be much more natural than that of my SC-55s and compatibles.

James-F wrote:There is no BANK to be selected here, only Patch, so there is no way to select a non-existent tone on channel 10.The game either uses a certain drum-kit or not, no room for mistakes.

So, circling back to this, the problem is that the SC-55 does allow for the selection of non-existent drum sets. Not only that, but, having done some thorough testing, I've discovered that the program change behavior for the drum sets is different between the 1.xx and 2.xx SC-55s.

Using my favorite Space Quest V example again, let's pretend for a moment that its retail driver actually passes the program change messages for channel 10 found in the original MIDI data. Wonderful! Except... the composer didn't RTFM and used PC# 51, which isn't a defined drum set in units prior to the SC-88, resulting in the following behavior:

SC-VA keeps the previous tone if an nonexistent variation is selected.Not anymore...

I have succeeded in creating CTF with MIDI-OX.Basically you create two Midi Loops with loopMIDI software "Midi OX In" and "Midi OX Out"

The first "Midi OX In" you point all your software to (Dosbox, Real PC, etc...).You can use a real Midi input on you USB midi dongle or audio interface, form your retro PC.The second "Midi OX Out" you connect your hardware to (SC-55 hardware, Plugins, etc..).Instead of "Midi OX Out" you can use your real Midi output from your audio interface or USB midi dongle.Any combination is possible.

Don't forget to rout input midi to output midi.

The secret sauce:In Midi-OX there is an option to create a "Translation Map".

As you can see I changed anything on CC#0 1-7 to 0, 9-15 to 8, 17-127 to 16.Now I have CTF on the first instrument on SC-55 no matter what version of SC-55 I use at the output.

The convenient thing is that I can do this with any midi command.I will create a Channel 10 CTF Preset for the Drum patches, so that all SC-55 units will behave like v1.xx with CTF on track 10.Stay tuned...

EDIT:

Took me 10 minutes to create a drum kit patch fallback.

All is working correctly, with all the programs I tried (dosbox, midi player).Now SC-VA drum patch change behaves like the SC-55 v1.xx unit Cloudschatze pointed.

I may do all instrument Preset for FULL CTF to all SC-55, but it may take some time.

This transformation fixes World of Xeen CTF when Walking (Footstep variation) and Shooting an Arrow (Acoustic Bass capital) on the same channel.After the transformation fix, on channel 9, when you shoot an arrow it first changes CC#0 to 0 (capital) and then calls for "Acoustic Bass", like it should be.Works perfectly with SC-VA.

The fun thing is that you can use your real retro PC with your real SC-55 unit, through a Midi USB dongle and an old laptop to run Midi-OX.Old PC -> USB Midi In - Laptop with Midi OX -> USB Midi Out -> SC-55.You can change patch/bank/sysex/NRPN behavior as you want and emulate SC-55 MK1 on a SC-55 MKII or later units.

EDIT:It was way easier than I thought, so I created a full and complete fallback transformation map.

This will load capital tones to patches that only have capital tones no matter what the CC#0 is wrongly set to.Patches that use banks/variations are un-affected.Channel 10 drum patches also fall to "first lowest" patch if a wrong patch number is sent, CC#0 is always changed to 0.

I used the SC-55 MK1 or MK2 instrument table (from manual) so select MK1 for accurate MK1 patch list (for example: Piano 1 has no variations in MK1 so it's always capital, etc...).There are two MK1 versions inside, v1.10 for "Fl, Key click" on patch #122 (non-GM), and v.21 for "Breath Noise" on patch #122 (GM).There is also a MK2 version but it is pointless because MK2 doesn't have CTF or a game that used that feature, but you can use it anyway.

Note that it will not change the actual sounds, but only the patch/bank change behavior, so you can use the SC-88 with your old games correctly.Also, you want to disable the transformation map when playing complex GS music midi files because drums may not always be only on channel 10.Let's just hope that game programmers were relying on CTF only on patches that have only capital tones (no Sub-capital variation 8,16,24,32).

Yes, Duke3D and Descent has the Key Click sound and Xeen interchanges between Footstep and Arrow correctly with MK1 v1 transformation.PS. Descent 1 and Doom are from 1994 and SC-55 MK1 v1 is from 1991, the probability that "Fl. Key Click" is the right instrument is NONE. Duke3D is from 1996 so definitely not Fl. Key Click.Prince of Persia 2 channel 10 plays correctly because the drums patch fallback fix.

I hope somebody finds this useful after all these decades.And... it's free, so you don't have to search for a MK1 SC-55 unit or modify the original game drivers/files.

Can you please compare v1.0, v1.2 and v2 (MK1) variations?I'm interested to know what differences are there between v1.0, v1.2 and v2.0 besides Key Click and Sinewave (variation), are there any more differences?

The manual from Roland of the SC-55 MK1 is for version 1.10, so no sinewave variation or breath noise.But what about v1.2 or v2.0 changes from v1.10? They are not documented anywhere.Are there more variations in v1.2 or v2.0 besides Sinewave?

Besides that, are you aware of any game that uses anything else than channel 10 for drums in GS mode (GM is always on 10)?Are you aware of any game that uses Sub-Capital tone fallback?Can you please test sub-capital tone fallback on v1.1, v1.2, v2.0, Silence or Fallback?

Sub-CTF according to MK1 manual (p43): from 0-7 falls to 0 (capital) from 8-15 falls to 8 (sub), from 16-23 falls to 16 (sub) on patches that have variations (not only capital).Programmer example: Let's use CC#0 12 because the SC-55 will automatically fall to CC#0 8, just because it works and 12 is me lucky nomba'... Sub-CTF is for the super-duper-mega lazy and careless programmer, and I really hope nobody EVER used that "feature" in MK1 between 1991 and 1994.

James-F wrote:I'm interested to know what differences are there between v1.0, v1.2 and v2.0 besides Key Click and Sinewave (variation), are there any more differences?

The 1.10 and 1.20/1 updates are mostly bugfixes, however, the Sine Wave and Breath Noise instruments were added with 1.20.

Version 2.00 adds one bugfix (that I suspect also comprises the 1.21 update), introduces the operational change of Rx. NRPN being set to Off with reception of a GM System On message, and additionally introduces the following "convenience" functions:

So, there is no known GS game that uses sub-CTF and only one game that uses different drum channel than 10.This is reassuring that the Midi-OX fix will do it's job just fine with GS games written for SC-55 MK1, and knowing that most games are GM anyway so I'll just leave it on 1.21 preset and forget it.This Midi-Ox fix is just another tool in my arsenal for better compatibility will less hardware.

Cloudschatze wrote:Using my favorite Space Quest V example again, let's pretend for a moment that its retail driver actually passes the program change messages for channel 10 found in the original MIDI data. Wonderful! Except... the composer didn't RTFM and used PC# 51, which isn't a defined drum set in units prior to the SC-88, resulting in the following behavior:

SC-55 1.xx - The Orchestra set is selected as the composer intended.

SC-55 2.xx - Silence - no drums for you!

SC-55mkII - Use of the Standard set is maintained.

SC-88 and above - The Kick&Snare set is selected.

Turns out this hypothetical scenario isn't so hypothetical after all - it's exactly the behavior presented by TFX, only with PC# 50 being used to select the Orchestra set instead of PC# 51 in the SQ5 example, and resulting in the following where used:

My own SC-55mkII has version 1.01. I have no information on what bugfix(es) it may contain over 1.00, however.

Cloudschatze wrote:Turns out this hypothetical scenario isn't so hypothetical after all - it's exactly the behavior presented by TFX, only with PC# 50 being used to select the Orchestra set...

So, this should surprise exactly no-one, given that Barry Leitch composed the soundtracks for both games, but Inferno: The Odyssey Continues, also sends PC# 50 to select the Orchestra drum set, and likewise uses multiple parts/channels for drums. In addition, several GS variation tones are used, including Sine Wave, further narrowing the ideal SC-55 target to a 1.20 or 1.21 unit.

There are definite sound differences between SC-VA and SC-55, "Stings" and "Choir Aahs" are clearly different.The SC-55 internal DACs distort if the volume control is at full volume, so it has to be lowered some.Apparently the Volume control is before the DAC, it might be even digital.

BTW, the Midi-OX fix working perfectly with the MKII, CTF fallback and Drum patch fallback.

So what's the deal with the mask roms that hold the samples? Their part numbers are the same between 1.10 and 1.21 units , could it be the case that they hold the same samples but the control rom of the 1.10 units for example just does not have the sine sound mapped?

IMHO there is a high chance that the sample roms are the same, Roland did change the cpu version and that resulted in a different part for the CPU and Control ROM ICs - surely they would also revise the part number of the sample roms if they were different. Too bad that swapping control roms doesn't work :\

James-F wrote:The SC-55 internal DACs distort if the volume control is at full volume, so it has to be lowered some.Apparently the Volume control is before the DAC, it might be even digital.

The volume knob is actually post-DAC, but prior to a pair of op-amps that drive the front and rear outputs. Sounds like a high volume setting will overdrive the op-amps to distortion, which is mostly consistent with other Roland gear.

keropi wrote:So what's the deal with the mask roms that hold the samples? Their part numbers are the same between 1.10 and 1.21 units , could it be the case that they hold the same samples but the control rom of the 1.10 units for example just does not have the sine sound mapped?

IMHO there is a high chance that the sample roms are the same, Roland did change the cpu version and that resulted in a different part for the CPU and Control ROM ICs - surely they would also revise the part number of the sample roms if they were different. Too bad that swapping control roms doesn't work :\

The Wave ROM chips are indeed exactly the same throughout all SC-55 versions. We'd have to see a 1.00 or 1.10 control ROM dump, but it's entirely possible that the Sine Wave instrument is actually defined, but is simply not selectable as part of the patch map, for whatever reason. The instruments/tones are really more than just direct mappings to the wave ROMs though - the SC-55 is a full-blown synthesizer under the hood, where several hundred bytes of non-user-accessible parameters define the sound, behavior, and characteristics of an individual tone.

^ So hypothetically someone that understands the control rom and its workings can patch it to work with older/newer cpu revisions... It would be great to have a patched rom with all the goodies and make every mk1 "optimal"

Cloudschatze wrote:The instruments/tones are really more than just direct mappings to the wave ROMs though - the SC-55 is a full-blown synthesizer under the hood, where several hundred bytes of non-user-accessible parameters define the sound, behavior, and characteristics of an individual tone.

Full-blown synth you say...So, it will not be as easy as just dumping the Wave ROM and emulating the Control chip to have something like MUNT.

keropi wrote:^ So hypothetically someone that understands the control rom and its workings can patch it to work with older/newer cpu revisions... It would be great to have a patched rom with all the goodies and make every mk1 "optimal"

Unfortunately this is likely to remain only a hypothetical possibility. You would have to disassemble the Control ROM code and maybe try to find a way to obtain the CPU ROM code from each unit version. I doubt that Roland invented a new CPU architecture and instruction set for the SC-55, but figuring out which architecture it adopted will prove a challenge. Then you would need to figure out how it works and what changes would need to be made.

Of course, in the interests of updating MIDI Module firmware, fixing the fast vibrato of the CM-500 & CM-32LN would be greatly appreciated I am sure.

I found undocumented instrument variations from SC-55 MKII that exist in the unit itself but not in the manual.Maybe that's some of the differences between ROM 1.00 and 1.01 of MKII?

CC#0=199=Syn Mallet103=Echo Bell105=Sitar 2

CC#0 = 2103=Echo Pan

CC#0 = 3124=Bird 2

CC#0 = 9119=Elec Perc

We can see that not only with the MK1 the instrument list has changed in the next version, also in MKII.The strange thing is that it's not documented anywhere and may have affected how composers used the unit, or not fully used the unit.Also, the CM-64 patch map at var 126 is missing from the SC-55 MKII official manual, only MT-32 patch map is specified at variation 127.

I counted 83 variations including undocumented.128 GM capitals with 128 MT-32 instruments and 10 drum kits (9 GS + 1 CM-32L) that would be 349 instruments overall in the MKII v1.01.5 instruments short of the 354 specified by wikipedia, and 5 more than documented in the MKII manual.

NewRisingSun and I have been looking at the control ROM data. Aside from that, the SC-55 being a synthesizer is more of just a common-sense statement though, and is likely applicable to every similar product.

James-F wrote:I found undocumented instrument variations from SC-55 MKII that exist in the unit itself but not in the manual.Maybe that's some of the differences between ROM 1.00 and 1.01 of MKII?

CC#0=199=Syn Mallet103=Echo Bell105=Sitar 2

CC#0 = 2103=Echo Pan

CC#0 = 9119=Elec Perc

We can see that not only with the MK1 the instrument list has changed in the next version, also in MKII.

There's also CC#0 = 3, PC#124=Bird 2.

These are all documented in a later version of the SC-55mkII manual. Since both the earlier and later manuals state the same total of 354 instruments, the "undocumented-ness" appears to be a simple typographic omission. Not knowing about these variations might certainly have precluded their use in compositions though.

Many internal test functions like, Memory Test, Battery Test, Midi Test, Effects Test, Output sine-wave to test for distortion with an oscilloscope.Volume control is indeed before a couple of op-amps according to the block diagram, so make sure they do not distort.Very handy to have this, you can download it.

@keropiAfter swapping ROMs you may try a "Factory Data Load" and a "Memory Test".